Improvements relating to intermittent driving-mechanism for feeding continuous stripmaterial

摘要

248,091. Forgrove Machinery Co., Ltd., and Grover, F. Dec. 1, 1924. Feeding and registering webs. - In apparatus for feeding strip material, such as a strip of wrapping material, intermittently in register with impressions on the strip, the feed device is adapted to feed a length of material greater or less than the distance between two impressions, the length to be fed at each feeding operation being selected automatically by the lowering of an electric contact brush or brushes on to the stationary strip the brushes coacting with conducting ink on the strip or with a metal part exposed by perforations in the strip. Each brush is in circuit with an electromagnet which controls the position of a member adapted to assume two positions with respect to a moving part of the feed device and thus determine whether a long or short feed shall be given to the strip on the next feeding operation. In one form, Fig. 1, the strip G of wrapping material perforated at intervals passes from a reel H round guide rollers H1, H2, over a metal contact stud J, and a guide roller H3 and between the feed rollers D to a severing knife F. The feed rollers are driven by gearing from a gear A operated by a friction ratchet gear comprising a pawl C having a notch C1 engaging an annular flange A2 on the gear A., the pawl being operated by a boss C2 oscillated by a link C3 and crank C4 on the driving shaft C5. Co-operating with the stud J are two contacts brushes K3, K4 on pivoted arms K, K1 which are raised and lowered by arms K5 on a shaft K7 rocked by connections K8, K9 from an arm R10 operated by a cam K12 on the shaft C5. The opposite sides of the gear A are frictionally engaged by arms L1, L2, Figs. 1 and 4, pivoted on a bracket L and one arm L1 has pivoted thereto a double-armed lever, one end M of which lies between two electromagnets N, N' in circuit with the brushes K3, K4 respectively, and the other arm of which is in the path of a member O mounted on the boss C2 and having two notches O1, O2 of different depths. At the end of each idle stroke of the pawl C, one of these notches engages the end M1 of the lever, thereby swinging the arm L2 to rotate the gear A so as to give a slight backward feed to the strip. According to whether the notch O2 or the notch O1 engages the lever, the backward feed is greater or less and the next forward feed is thus a short one or a long one. In the operation of the machine, if the strip is in advance of its correct position the brush K3 makes contact through a perforation in the strip and closes a circuit to excite the electromagnet N, which thereupon attracts the arm M to bring the end M1 into the path of the notch O2. If the strip is behind its correct position, the brush K4 makes contact through a perforation in the strip and closes a circuit to the electromagnet N1 whereby the arm N1 is brought into the path of the notch O1. In the form shown in Fig. 5, a single brush K3 is provided, adapted, upon passing through a perforation in the strip, to close a circuit to energize an electromagnet N which thereupon attracts one end P of a lever. A stop Q on the other end of the lever is thereby moved into the path of the pawl C and arrests it before it has completed its normal idle movement. The next operative movement of the pawl is thus shortened and the shorter length of strip is fed. Specifications 177,321 and 220,805 are referred to.